He and his girlfriend, /*Chie Alexandra Coggins Johnson*/, 20, are facing murder charges. She has also pleaded not guilty to murder.
/*Katsutoshi Tony Takazato*/, son of filmmaker /*Fuminori Hayashida*/, was found dead at about 6 a.m. Tuesday outside his home in 1800 block of Carla Ridge in the exclusive /*Trousdale Estates*/ area.
Prosecutors say Barker became enraged after Johnson told him that Takazato, who she used to date, had physically abused her.
A third person who was arrested was released after the investigation concluded he wasn't involved in the slaying.
The couple faces life in prison if convicted.
The Associated Press contributed to this report.